Factor chromeos::TabletState::State out into //display/tablet_state.h

This CL is a preparation CL, where the final goal is to move
away from using chromeos::TabletState, embedding its functionality
into //display/ScreenBase class.

The first step to to dismantle this enum from it, so that it can
be referenced to independently.

TBR=jamescook@chromium.org

BUG=1113900
R=jamescook@chromium.org, oshima@chromium.org, rjkroege@chromium.org

Change-Id: I4d907b9d322723f581bfc1a278577088028795ce
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2505944
Commit-Queue: Antonio Gomes <tonikitoo@igalia.com>
Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822105}

ash/wm/tablet_mode/tablet_mode_controller.cc

@@ -48,6 +48,7 @@
 #include "ui/compositor/layer_animation_sequence.h"
 #include "ui/display/display.h"
 #include "ui/display/manager/display_manager.h"
+#include "ui/display/tablet_state.h"
 #include "ui/events/devices/device_data_manager.h"
 #include "ui/events/devices/input_device.h"
 #include "ui/events/event.h"
@@ -492,8 +493,8 @@ bool TabletModeController::TriggerRecordLidAngleTimerForTesting() {
 void TabletModeController::MaybeObserveBoundsAnimation(aura::Window* window) {
   StopObservingAnimation(/*record_stats=*/false, /*delete_screenshot=*/false);
 
-  if (tablet_state_.state() != chromeos::TabletState::kEnteringTabletMode &&
-      tablet_state_.state() != chromeos::TabletState::kExitingTabletMode) {
+  if (tablet_state_.state() != display::TabletState::kEnteringTabletMode &&
+      tablet_state_.state() != display::TabletState::kExitingTabletMode) {
     return;
   }
 
@@ -794,7 +795,7 @@ void TabletModeController::OnLayerAnimationScheduled(
         animating_layer_->GetCompositor()->RequestNewThroughputTracker();
     transition_tracker_->Start(metrics_util::ForSmoothness(base::BindRepeating(
         &ReportTrasitionSmoothness,
-        tablet_state_.state() == chromeos::TabletState::kEnteringTabletMode)));
+        tablet_state_.state() == display::TabletState::kEnteringTabletMode)));
     return;
   }
 
@@ -840,7 +841,7 @@ void TabletModeController::SetTabletModeEnabledInternal(bool should_enable) {
   DeleteScreenshot();
 
   if (should_enable) {
-    tablet_state_.SetState(chromeos::TabletState::kEnteringTabletMode);
+    tablet_state_.SetState(display::TabletState::kEnteringTabletMode);
 
     // Take a screenshot if there is a top window that will get animated.
     // TODO(sammiequon): Handle the case where the top window is not on the
@@ -870,7 +871,7 @@ void TabletModeController::SetTabletModeEnabledInternal(bool should_enable) {
       FinishInitTabletMode();
     }
   } else {
-    tablet_state_.SetState(chromeos::TabletState::kExitingTabletMode);
+    tablet_state_.SetState(display::TabletState::kExitingTabletMode);
 
     // We may have entered tablet mode, then tried to exit before the screenshot
     // was taken. In this case |tablet_mode_window_manager_| will be null.
@@ -886,7 +887,7 @@ void TabletModeController::SetTabletModeEnabledInternal(bool should_enable) {
 
     base::RecordAction(base::UserMetricsAction("Touchview_Disabled"));
     RecordTabletModeUsageInterval(TABLET_MODE_INTERVAL_ACTIVE);
-    tablet_state_.SetState(chromeos::TabletState::kInClamshellMode);
+    tablet_state_.SetState(display::TabletState::kInClamshellMode);
     for (auto& observer : tablet_mode_observers_)
       observer.OnTabletModeEnded();
     VLOG(1) << "Exit tablet mode.";
@@ -1130,7 +1131,7 @@ void TabletModeController::ResetPauser() {
 }
 
 void TabletModeController::FinishInitTabletMode() {
-  DCHECK_EQ(chromeos::TabletState::kEnteringTabletMode, tablet_state_.state());
+  DCHECK_EQ(display::TabletState::kEnteringTabletMode, tablet_state_.state());
 
   for (auto& observer : tablet_mode_observers_)
     observer.OnTabletModeStarting();
@@ -1139,7 +1140,7 @@ void TabletModeController::FinishInitTabletMode() {
 
   base::RecordAction(base::UserMetricsAction("Touchview_Enabled"));
   RecordTabletModeUsageInterval(TABLET_MODE_INTERVAL_INACTIVE);
-  tablet_state_.SetState(chromeos::TabletState::kInTabletMode);
+  tablet_state_.SetState(display::TabletState::kInTabletMode);
 
   for (auto& observer : tablet_mode_observers_)
     observer.OnTabletModeStarted();

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.cc

@@ -415,16 +415,16 @@ gfx::ImageSkia BrowserNonClientFrameViewAsh::GetFrameHeaderOverlayImage(
 }
 
 void BrowserNonClientFrameViewAsh::OnTabletStateChanged(
-    chromeos::TabletState::State state) {
+    display::TabletState state) {
   switch (state) {
-    case chromeos::TabletState::State::kInTabletMode:
+    case display::TabletState::kInTabletMode:
       OnTabletModeToggled(true);
       return;
-    case chromeos::TabletState::State::kInClamshellMode:
+    case display::TabletState::kInClamshellMode:
       OnTabletModeToggled(false);
       return;
-    case chromeos::TabletState::State::kEnteringTabletMode:
-    case chromeos::TabletState::State::kExitingTabletMode:
+    case display::TabletState::kEnteringTabletMode:
+    case display::TabletState::kExitingTabletMode:
       break;
   }
 }

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h

@@ -18,6 +18,7 @@
 #include "chromeos/ui/base/tablet_state.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_observer.h"
+#include "ui/display/tablet_state.h"
 
 namespace {
 class WebAppNonClientFrameViewAshTest;
@@ -82,7 +83,7 @@ class BrowserNonClientFrameViewAsh
   gfx::ImageSkia GetFrameHeaderOverlayImage(bool active) override;
 
   // chromeos::TabletState::Observer:
-  void OnTabletStateChanged(chromeos::TabletState::State) override;
+  void OnTabletStateChanged(display::TabletState state) override;
 
   void OnTabletModeToggled(bool enabled);
 

chromeos/ui/base/BUILD.gn

@@ -29,6 +29,7 @@ component("base") {
     "//base",
     "//skia",
     "//ui/base",
+    "//ui/display",
     "//ui/gfx/geometry",
   ]
 }

chromeos/ui/base/DEPS

 include_rules = [
-  "+ui/base",
   "+third_party/skia",
+  "+ui/base",
+  "+ui/display",
   "+ui/gfx",
 ]

chromeos/ui/base/tablet_state.cc

@@ -35,11 +35,11 @@ void TabletState::RemoveObserver(Observer* observer) {
 }
 
 bool TabletState::InTabletMode() const {
-  return state_ == TabletState::kInTabletMode ||
-         state_ == TabletState::kEnteringTabletMode;
+  return state_ == display::TabletState::kInTabletMode ||
+         state_ == display::TabletState::kEnteringTabletMode;
 }
 
-void TabletState::SetState(State state) {
+void TabletState::SetState(display::TabletState state) {
   state_ = state;
 
   for (auto& observer : observers_)

chromeos/ui/base/tablet_state.h

@@ -7,6 +7,7 @@
 
 #include "base/component_export.h"
 #include "base/observer_list.h"
+#include "ui/display/tablet_state.h"
 
 namespace ash {
 class TabletModeController;
@@ -23,18 +24,9 @@ class COMPONENT_EXPORT(CHROMEOS_UI_BASE) TabletState {
   // Returns the singleton instance.
   static TabletState* Get();
 
-  // Tracks whether we are in the process of entering or exiting tablet mode.
-  // Used for logging histogram metrics.
-  enum State {
-    kInClamshellMode,
-    kEnteringTabletMode,
-    kInTabletMode,
-    kExitingTabletMode,
-  };
-
   class COMPONENT_EXPORT(CHROMEOS_UI_BASE) Observer {
    public:
-    virtual void OnTabletStateChanged(State state) = 0;
+    virtual void OnTabletStateChanged(display::TabletState state) = 0;
 
    protected:
     virtual ~Observer() = default;
@@ -51,18 +43,18 @@ class COMPONENT_EXPORT(CHROMEOS_UI_BASE) TabletState {
   // Returns true if the system is in tablet mode.
   bool InTabletMode() const;
 
-  State state() const { return state_; }
+  display::TabletState state() const { return state_; }
 
  private:
   // The friend class declaration here is used to control classes that can set
   // the tablet state.
   friend class ash::TabletModeController;
 
-  void SetState(State state);
+  void SetState(display::TabletState state);
 
   base::ObserverList<Observer>::Unchecked observers_;
 
-  State state_ = State::kInClamshellMode;
+  display::TabletState state_ = display::TabletState::kInClamshellMode;
 };
 
 }  // namespace chromeos

ui/display/BUILD.gn

@@ -35,6 +35,7 @@ component("display") {
     "screen.h",
     "screen_base.cc",
     "screen_base.h",
+    "tablet_state.h",
     "unified_desktop_utils.cc",
     "unified_desktop_utils.h",
   ]

ui/display/tablet_state.h

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_DISPLAY_TABLET_STATE_H_
+#define UI_DISPLAY_TABLET_STATE_H_
+
+namespace display {
+
+// Tracks whether we are in the process of entering or exiting tablet mode.
+enum class TabletState {
+  kInClamshellMode,
+  kEnteringTabletMode,
+  kInTabletMode,
+  kExitingTabletMode,
+};
+
+}  // namespace display
+
+#endif  // UI_DISPLAY_TABLET_STATE_H_